JP4246331B2 - Metallic glossy temperature-changing heat-shrinkable plastic film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a metallic glossy temperature-changing heat-shrinkable plastic film. More specifically, the present invention relates to a metallic luster-like temperature-changeable heat-shrinkable plastic film that exhibits various color changes of metallic luster and has improved light fastness.
[0002]
[Prior art]
  Conventionally, several thermosensitive color-shrinkable plastic films provided with a thermochromic layer in which a thermochromic pigment is contained in a binder resin in a dispersed state, and articles on which the film is mounted by heat-shrink processing, Proposals have been disclosed (Japanese Utility Model Laid-Open No. 1-80489, Japanese Utility Model Laid-Open No. 60-75229, Japanese Utility Model Laid-Open No. 62-17529, Japanese Utility Model Publication No. 4-25321).
[0003]
[Problems to be solved by the invention]
  The present invention provides a new thermosensitive color-changing heat shrinkage that adds a variety of metallic glossy color-changing functions and prevents a decrease in light resistance of the thermochromic layer in this type of thermochromic heat-shrinkable plastic film. It is intended to provide a flexible plastic film and to be applied to various fields as a packaging material.
[0004]
[Means for Solving the Problems]
  The present invention will be described with reference to the drawings (see FIGS. 1 to 8).
  In the present invention, a part or the entire surface of the heat-shrinkable plastic film 2 isA metallic luster pigment coated with titanium oxide on the surface of a flat glass piece was fixed to a binder resin in a dispersed state.The metallic gloss pigment layer 3 is provided, and the thermochromic layer 4 is laminated on the metallic gloss pigment layer 3, and the metallic gloss tone temperature-changing heat-shrinkable plastic film 1 is a requirement. To do.
  Furthermore,heatThe color-changing layer 4 is a layer in which a thermochromic pigment is fixed to a binder resin in a dispersed state, and the thermochromic pigment is decolored by heating from the colored state and is colored by cooling from the decolored state. Color erasure type, color development state or color memory retention type that retains and retains the color erasure state in a specific temperature range, or color development by heating from the color erasure state, and restoration to the color erasure state by temperature decrease from the color development state In addition, the thermochromic pigment is selected from (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a color reaction of the both. And a non-circular cross-sectional microcapsule-like pigment that contains a thermochromic composition containing the essential three components consisting of a reaction medium that determines the occurrence temperature of the liquid.
[0005]
  As the heat-shrinkable plastic film 2 described above, a uniaxial or biaxially stretched film such as polyester, polystyrene, polyethylene, polypropylene, polyvinylidene chloride, polyvinyl chloride or the like, which has been conventionally used, can be applied and has a thickness of about several μm to several mm. Can be used as appropriate. Among these, a colorless and transparent plastic film is preferable in order to make the metallic gloss color clearly visible.
  The main object of the present invention is to provide a variety of functions for changing the color of metallic luster such as gold, silver, and metallic colors due to temperature changes, and to provide a function for preventing the light fastness of the thermochromic layer 4 from being lowered. Is.
  Conventionally, as a means for suppressing a decrease in light resistance of the thermochromic layer, a light reflecting or absorbing layer is provided between the plastic film and the thermochromic layer, and the lower thermochromic layer is formed by reflecting and absorbing ultraviolet rays and visible rays. However, the light absorption layer is not colorless and is slightly colored (white or blackish), which hinders the visual effect of the thermochromic layer.
  The metallic luster pigment layer 3 in the present invention has both a light absorption (or light reflection) function and a light transmission function, and absorbs or absorbs at least a part of ultraviolet rays and visible rays which adversely affect the function deterioration of the thermochromic layer. Reflects, thereby suppressing the light fastness of the thermochromic layer, and can transmit an appropriate amount of visible light that does not interfere with vision, and effectively visualize the color change of the thermochromic layer. Can do.
  Further, since the metallic gloss layer 3 is visualized through the heat-shrinkable plastic film 2, a unique metallic gloss pigment layer can be visualized in combination with the glossiness of the film surface. Further, at the time of shrinkage, simultaneously with the shrinkage of the heat-shrinkable plastic film, the metallic luster pigment is made dense, and the glitter is further improved.
[0006]
  Next, the metallic luster pigment will be described.
  The pigment in the metallic luster pigment layer 3 is,sideThe following metallic luster pigments in which the surface of a flat glass piece is coated with titanium oxideForI can.
  As a pigment in which the surface of a flat glass piece is coated with titanium oxide, a trade name “Metashine” manufactured by Nippon Glass Fiber Co., Ltd .: RCFSX-5450TS (6041) [average thickness 5 ± 2 μm, average particle size 450 ± 145 μm , Gold], RCFSX-5200TS (6042) [average thickness 5 ± 2 μm, average grain size 200 ± 70 μm, silver], RCFSX-5140TS (6043) [average thickness 5 ± 2 μm, average grain size 140 ± 45 μm, silver] RCFSX-5080TS (6044) [average thickness 5 ± 2 μm, average grain size 80 ± 30 μm, silver color], RCFSX-2080TS (6046) [average thickness 2 ± 1 μm, average grain size 80 ± 30 μm, silver color], RCFSX-K120TS ( 6043) [average thickness 20 ± 5 μm, average grain size 120 ± 20 μm, silver], RCFSX-5090RC ( 052) [average thickness 5 ± 2 μm, average particle size 90 ± 30 μm, gold color], RCFSX-5090RC (8053) [average thickness 5 ± 2 μm, average particle size 80 ± 30 μm, metallic green], RCFSX-5090RC (8069) [average Thickness 5 ± 2 μm, average particle size 90 ± 30 μm, metallic blue], RCFSX-5090RC (8070) [average thickness 5 ± 2 μm, average particle size 90 ± 30 μm, metallic purple], RCFSX-5090RC (8071) [average thickness 5 ± 2 μm, average particle size 90 ± 30 μm, metallic red] and the like.
  Since the pigment having the surface of the flat glass piece coated with titanium oxide uses the flat glass piece as a core substance, it has a characteristic of being excellent in transparency as compared with the pigment having the surface of mica coated with titanium oxide. .
[0007]
  The binder resin for fixing the metallic luster pigment in a dispersed state may be a transparent film-forming resin, and conventionally used resins such as ionomer resins, isobutylene-maleic anhydride resin copolymer resins, acrylonitrile-acrylic styrene. Copolymer resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile chlorinated polyethylene-styrene copolymer resin, ethylene-vinyl chloride copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl acetate -Vinyl chloride graft copolymer resin, vinylidene chloride resin, vinyl chloride resin, chlorinated vinyl chloride resin, vinyl chloride-vinylidene chloride copolymer resin, chlorinated polyethylene resin, chlorinated polypropylene resin, polyamide resin, polyethylene tele Talate resin, polybutylene terephthalate resin, polycarbonate resin, polystyrene resin, high impact polystyrene resin, polypropylene resin, polymethylstyrene resin, polyacrylate resin, polymethyl methacrylate resin, epoxy acrylate resin, alkylphenol resin, rosin modified phenol resin, Rosin modified alkyd resin, phenol resin modified alkyd resin, epoxy resin modified alkyd resin, styrene modified alkyd resin, acrylic modified alkyd resin, amino alkyd resin, vinyl chloride-vinyl acetate resin, styrene-butadiene resin, epoxy resin, unsaturated polyester resin , Saturated polyester resin, polyurethane resin, alkyd resin, natural rubber, polyisobutylene, butyl rubber, polyvinyl alkyl ether Rosin, rosin ester, rosin derivative, polyterpene resin, oil-soluble phenol resin, petroleum hydrocarbon resin, shellac, cyclized rubber, vinyl acetate emulsion resin, styrene-butadiene emulsion resin, acrylate emulsion resin, Water-soluble alkyd resins, water-soluble melamine resins, water-soluble urea resins, water-soluble phenol resins, water-soluble epoxy resins, water-soluble polybutadiene resins, cellulose acetate cellulose, cellulose nitrate, ethyl cellulose, etc. A vehicle for dispersing the metallic luster pigment can be obtained by dissolving or dispersing in an appropriate solvent.
[0008]
  The thermochromic layer 4 is formed in a laminated state on the metallic luster pigment layer 3 (see FIG. 1).
  The thermochromic pigment comprises (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound that colors the compound, and (c) a reaction medium that determines the temperature at which the color reaction of the both occurs. A microcapsulation of a conventionally known heat-discoloring type thermochromic composition containing the essential three components is effective, specifically, Japanese Patent Publication No. 51-44706, proposed by the present applicant, Those described in JP-B-51-44707, JP-B-1-29398 and the like can be used. The above color changes before and after a predetermined temperature (discoloration point), exhibits a decolored state at a temperature range above the discoloration point, and develops a color state at a temperature range below the discoloration point. Only one of the states can exist. That is, the other state is maintained while the heat or cold heat required to develop the state is applied, but when the heat or cold heat is no longer applied, the state returns to the normal temperature range. In addition, the hysteresis width is relatively small (ΔH_A= 1 to 7 ° C.), which can be exemplified by a heat decoloring type (A), ΔH_AIs a system having a temperature of 3 ° C. or lower (a fatty acid ester having a ΔT value (melting point-cloud point) of 3 ° C. or lower as shown in Japanese Examined Patent Publication No. 1-29398 is applied as the component (c)). Is sensitive to changes in temperature and exhibits high sensitivity to heat decolorization._AHowever, in a system having a temperature of about 4 to 7 ° C., after the color change, it gradually returns to the original appearance and the visual effect can be enhanced (see FIG. 6).
[0009]
  In addition, the large hysteresis characteristics (ΔH described in Japanese Patent Publication No. 4-17154, Japanese Patent Application Laid-Open No. 7-179777, Japanese Patent Application Laid-Open No. 7-33997, Japanese Patent Application Laid-Open No. 8-39936, etc. proposed by the present applicant._B= 8 to 50 ° C.), that is, the shape of the curve plotting the change of the color density due to the temperature change is opposite to the case where the temperature is raised from the lower temperature side than the color change temperature range, from the higher temperature side than the color change temperature range. The color changes by following a path that is greatly different from the case of lowering, and t₁Color development state in the following low temperature range, or t₄The decolored state in the above high temperature range is the specific temperature range [t₂~ T₃A color memory retention type thermochromic composition (B) that can be stored and retained in a temperature range between (a substantially two-phase retention temperature range)] is also applicable (see FIG. 7).
  The substantially two-phase holding temperature range includes a normal temperature range (for example, 15 to 35 ° C.), but is not limited to the temperature range.
[0010]
  According to the proposals of the present applicant (Japanese Patent Laid-Open Nos. 11-129623 and 11-5973) that develop color by heating from a decolored state as the composition of the heat-coloring type (C), (b) Examples of the electron-accepting compound include a system to which a specific alkoxyphenol compound having a linear or side chain alkyl group having 3 to 18 carbon atoms is applied (see FIG. 8).
[0011]
  The present invention applies a pigment in the form of a microcapsule in which the thermochromic composition described above is encapsulated in a microcapsule.
  As a means for encapsulating the thermochromic composition in a capsule, a known encapsulation method such as an interfacial polymerization method, an interfacial polycondensation method, an in situ method, or a coacervate method is applied. In order to obtain a thermochromic pigment having a particle diameter range and an outer shape to be satisfied, an interfacial polymerization method or an interfacial polycondensation method that hardly causes aggregation and coalescence is preferably used. Furthermore, after completion of the encapsulation, unnecessary coarse particles are removed by diluting the capsule suspension with water as desired, and filtering out impurities and coarse particles using filters.
[0012]
  The average particle size [(major axis + minor axis) / 2] of the thermochromic pigment is in the range of 0.5 μm to 30 μm, preferably 0.5 to 15 μm, more preferably 0.5 to 10 μm. Is effective in terms of color change sensitivity, endurance, processability, and the like.
  In a system having a particle diameter of more than 30 μm, it is difficult to achieve a stable color thermochromic function because it lacks homogeneous dispersibility and is easily affected by shrinkage stress during heat shrink processing.
  In a system of less than 0.5 μm, even if a thermochromic pigment microencapsulated in a suspended state in an aqueous medium is obtained, the encapsulated pigment can be isolated by means such as filtration or centrifugation. There are difficulties and strength is insufficient.
[0013]
  In the encapsulated thermochromic pigment of the present invention, it is desirable that the thermochromic composition / microcapsule wall film = 7/1 to 1/1 (weight ratio).
  When the ratio of the thermochromic composition is larger than the above range, the thickness of the wall film becomes too thin, and the protective function of the encapsulated thermochromic composition is reduced.
  On the other hand, when the ratio of the wall film is larger than the above range, the wall film strength is improved and the protective function is improved, but the color density is inevitably decreased due to the decrease in the relative ratio of the thermochromic composition, which is not preferable. .
[0014]
  The thermochromic pigment is preferably a flat pigment having a non-circular cross-sectional shape (see FIGS. 2 to 5). By applying the flat pigment, the heat associated with the contraction stress at the time of thermal contraction of the film is obtained. When the color-changing layer 4 is contracted, the thermochromic pigment itself is elastically deformed in accordance with the stress to suppress the occurrence of shrinkage unevenness, and the homogeneity of the thermochromic layer 4 is not impaired.
  In addition, in a system that shrinks the surface of deformable containers and metallic materials with a thick and high-temperature shrinkable film, even if high pressure shrinkage stress or high temperature is applied, the capsule wall membrane is destroyed. Is a tough capsule form that can be elastically deformed appropriately to avoid the stress, relieve stress, protect the thermochromic composition of the encapsulated body, and continuously and effectively express without impairing the desired thermochromic function It functions effectively as a thermochromic pigment.
[0015]
  The thermochromic pigment is dispersed in a predetermined amount in a vehicle containing a binder resin to form an ink or paint, and the thermochromic layer 4 is formed by conventional printing or coating means. Here, the thermochromic pigment is blended at a ratio of 20 to 400 parts by weight with respect to 100 parts by weight of the binder resin. If it is less than 20 parts by weight, no clear thermochromic property is exhibited. On the other hand, if it exceeds 400 parts by weight, a color residue at the time of decoloring tends to occur, and it is preferably applied in the range of 50 to 350 parts by weight.
  In addition, the said binder resin is suitably selected according to the objective from the binder resin applied to the metallic luster pigment as stated above, and is applied.
[0016]
  The thermochromic layer 4 is not limited to a single layer in which one or a plurality of thermochromic pigments having different color temperature, color tone, and color change characteristics are blended in the layer, and the color change point, color tone, density, etc. A multi-layer structure in which thermochromic layers using different thermochromic pigments are overprinted, one in which thermochromic layers are arranged in parallel, and color (1) to colored (in combination with a non-thermochromic colorant ( A structure for changing to 2) and an overprinting system with a non-thermochromic layer are effective.
  In the above description, the thermochromic layer 4 or the metallic luster pigment layer 3 is not limited to a solid print, and includes images such as letters, symbols, numbers, and designs.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
  The metallic luster-sensitive temperature-changing heat-shrinkable plastic film of the present invention is obtained by laminating a metallic luster pigment layer and a thermochromic layer on the surface of a heat-shrinkable plastic film.
  The laminated structure described above is not limited to a single image, and images having the same or different color tone, color change temperature, color change characteristics, etc. may be separately provided. Each of the metallic gloss image and the thermochromic image is a single layer. In addition, images having the same or different color tone, color change temperature, color change characteristics, and the like may be laminated.
  Moreover, you may provide the image of each single layer of a metallic luster image and a thermochromic image separately from the said laminated structure.
  Furthermore, in order to enhance the visual effect, a non-thermo-discolored image can be laminated on the above structure or provided separately.
[0018]
【Example】
  In the following, examples of the metallic gloss tone temperature-changing heat-shrinkable plastic film of the present invention will be described. In addition, the part in an Example shows a weight part.
[0019]
[0020]
  Example1
  An acrylic resin containing 60 parts of a silver metallic luster pigment having an average thickness of 5 ± 2 μm and an average particle size of 80 ± 30 μm, which is obtained by coating the surface of a flat glass piece with titanium oxide on a heat-shrinkable film made of transparent polystyrene resin having a thickness of 60 μm. (Solid content 40% by weight) After providing a metallic gloss image with a metallic luster ink dispersed in a vehicle containing 80 parts and 2 parts of an antifoaming agent, a reversible thermochromic pigment (colored 18 ° C., decolored 30 ° C. , Black ← → colorless, color memory retention type) The metallic gloss image with thermochromic ink dispersed in a vehicle containing 80 parts of acrylic resin (solid content 40 wt%) and 2 parts of antifoaming agent A thermochromic image was laminated thereon to obtain a metallic luster-sensitive temperature-changing heat-shrinkable plastic film.
  When the film, which was colorless at room temperature (25 ° C.), was cooled to 18 ° C. or less, it became a glittering and shiny silver color, and this state could be maintained even when heated to room temperature (25 ° C.) again. Furthermore, by heating from the silver colored state, it returned to colorless at about 30 ° C., and this state could be maintained until it was cooled again to 18 ° C. or less. The discoloration could be reproduced reversibly and repeatedly.
[0021]
[0022]
[0023]
  Example2
  An acrylic resin containing 60 parts of a silver metallic luster pigment having an average thickness of 5 ± 2 μm and an average particle size of 80 ± 30 μm, which is obtained by coating the surface of a flat glass piece with titanium oxide on a heat-shrinkable film made of transparent polystyrene resin having a thickness of 60 μm. (Solid content 40% by weight) After providing a metallic gloss image with a metallic luster ink dispersed in a vehicle containing 80 parts and an antifoaming agent 2 parts, a reversible thermochromic pigment (coloring 12 ° C., decoloring 15 ° C. , Black ← → colorless, heat-erasable type) 100 parts of a thermochromic ink dispersed in a vehicle containing 80 parts of an acrylic resin (solid content 40% by weight) and 2 parts of an antifoaming agent, and non-thermochromic A thermochromic image and a non-thermochromic image were sequentially laminated on the metallic gloss image with a yellow ink, respectively, to obtain a metallic glossy temperature-sensitive color-changing heat-shrinkable plastic film.
  The film exhibited a yellow color at 15 ° C. or higher, and exhibited a lustrous silvery color when cooled to 12 ° C. or lower. The discoloration could be reproduced reversibly and repeatedly.
[0024]
  Example3
  An average of 20 parts of metallic green colored metallic luster pigment coated with 56% by weight of titanium oxide on a heat-shrinkable film made of transparent polyester resin having a thickness of 40 μm, and a surface of a flat glass piece coated with titanium oxide. Metallic luster dispersed in a vehicle containing 80 parts of an acrylic resin (solid content 40% by weight) and 2 parts of an antifoaming agent 60 parts of a metallic purple colored metallic luster pigment having a thickness of 5 ± 2 μm and an average particle size of 90 ± 30 μm Two types of metallic gloss images with different colors were provided with ink.
  Next, 100 parts of reversible thermochromic pigment (colored 12 ° C., decolored 15 ° C., green ← → colorless, heat decolored type), reversible thermochromic pigment (colored 12 ° C., decolored 15 ° C., pink color →→ colorless) On the metallic green metallic glossy image, 100 parts of heat-decoloring type is dispersed in a vehicle containing 80 parts of acrylic resin (solid content 40% by weight) and 2 parts of antifoaming agent. A green ← → colorless thermochromic image and a pink ← → colorless thermochromic image on a metallic purple metallic gloss image were laminated to obtain a metallic luster-sensitive temperature-changing heat-shrinkable plastic film. .
  The film was colorless at 15 ° C. or higher, and when cooled to 12 ° C. or lower, it exhibited a shiny metallic green color and a shiny metallic purple color. The discoloration could be reproduced reversibly and repeatedly.
[0025]
[0026]
  Application examples1
  An acrylic resin containing 60 parts of a silver metallic luster pigment having an average thickness of 5 ± 2 μm and an average particle size of 80 ± 30 μm, which is obtained by coating the surface of a flat glass piece with titanium oxide on a heat-shrinkable film made of transparent polystyrene resin having a thickness of 60 μm. (A solid content of 40% by weight) After providing an oval solid metal gloss image by gravure printing with a metal gloss ink dispersed in a vehicle containing 80 parts and an antifoam agent 2 parts, a reversible thermochromic pigment (Colored 12 ° C., decolored 15 ° C., black ← → colorless, heat decolored mold) 100 parts heat dispersed in a vehicle containing 80 parts acrylic resin (solid content 40 wt%) and 2 parts defoamer A thermochromic image of the letter "cold" on the metallic gloss image with a color-changing ink, and a non-thermochromic white ink layered by gravure printing to further enhance the visual effect. Obtained heat shrinkable plastic film .
  Next, after attaching the end of the film in a cylindrical shape so that the printing surface is on the inside, the film was attached to a polyester resin beverage container and subjected to heat shrink processing to constitute a temperature-sensitive discolorable beverage container. .
  In the beverage container, only a white oval shape was visually recognized at room temperature (25 ° C.), but when it was cooled to 12 ° C. or lower in a refrigerator, a shiny and silvery “cold” character appeared. When the temperature returns to room temperature, the characters disappear, and only the original oval pattern is visible, and can be used as a cold beverage container.
[0027]
  Application examples2
  Metallic blue color with an average thickness of 5 ± 2μm and average particle size of 90 ± 30μm, with the surface of flat glass pieces covered with titanium oxide on an anchor coat formed on the surface of a heat-shrinkable film made of transparent polyethylene resin with a thickness of 1.5mm In a vehicle containing 80 parts of a metallic luster pigment, 40 parts of a vinyl acetate emulsion resin (solid content 50% by weight), 20 parts of a water-soluble alkyd resin (solid content 30% by weight), 1 part of a viscosity modifier and 3 parts of an antifoaming agent After a solid glossy metal image is provided by screen printing with a metallic glossy ink dispersed on the surface, a reversible thermochromic pigment (colored 32 ° C., decolored 35 ° C., blue ← → colorless, heat decolored type) 40 Parts and 40 parts of a vinyl acetate emulsion resin (solid content 50% by weight), 20 parts of a water-soluble alkyd resin (solid content 30% by weight), 1 part of a viscosity modifier and 3 parts of an antifoaming agent To obtain a metal luster thermochromic heat shrinkable plastic film in the same manner as thermochromic image of a solid pattern on the metallic luster image at dispersed allowed thermochromic ink by laminating by screen printing in Hikuru.
  The film was wrapped around a pipe made of vinyl chloride resin for liquid feeding, and the ends were bonded, and then heat shrinkage was applied to obtain a thermochromic pipe.
  The pipe normally has a brilliant and shiny metallic blue color. However, when hot water of 40 ° C. or higher was passed through the pipe, the pipe showed a fluorescent pink color, and the hot water feeding state could be discriminated at a glance. The hot water supply was stopped and after a while the original metallic blue color was restored.
[0028]
[0029]
[0030]
【The invention's effect】
  In addition to the conventional temperature-sensitive color-changing function, the metallic gloss-type temperature-changeable heat-shrinkable film of the present invention has a variety of metal-glossy color-changing functions and improved light fastness. Therefore, it satisfies the practicality as a new heat-shrinkable plastic film that continuously develops the desired metallic gloss tone temperature-changing function without deteriorating the heat-changing function.
  In addition, in a system to which a microcapsule-type thermochromic pigment having a non-circular cross-sectional shape is applied, even when high temperature and high pressure are applied during heat shrinkage processing or in use, the load is relieved by elastic deformation of the pigment itself. In addition, the microcapsule membrane is not destroyed, and the desired thermochromic function can be sustained and effectively expressed. Various conventional fields such as beverage containers, aerosol cans, toiletries, household goods, electricity For applications such as labels, coatings, packaging, etc. for products, dry batteries, electric wires, liquid pipes, fruits and vegetables, confectionery, foods, writing instruments, toys, sports equipment, etc. It can be given relatively easily.
  Further, as a thermochromic pigment, in a system having a hysteresis width of less than 3 ° C., the thermochromic pigment quickly returns to the original color after thermal discoloration, and in a system having a hysteresis width of approximately 4-8 ° C., Slowly return to the original color to enhance the visual effect, and in a large system with a hysteresis width exceeding 8 ° C, the color memory function is expressed, even after removing the heat or cold necessary for discoloration, The colors before and after the color change can be stored in a reciprocal manner so that they can be viewed alternatively in the normal temperature range. Furthermore, in the case of a heating coloring type system, a normally invisible image can be displayed by heating. . Furthermore, a metallic luster that makes it possible to visualize more various aspects by overprinting or juxtaposing thermochromic layers with thermochromic pigments having different color-changing forms as described above or in combination with non-thermochromic colored layers. It can function as a temperature-sensitive color-changing heat-shrinkable plastic film.
[Brief description of the drawings]
FIG. 1 is a longitudinal cross-sectional explanatory view of a metallic glossy temperature-sensitive color-changing heat-shrinkable plastic film of the present invention.
FIG. 2 is an enlarged explanatory view of (a) an appearance and (b) a cross section showing an example of a thermochromic pigment constituting the present invention.
FIG. 3 is an enlarged explanatory view of (a) the appearance and (b) the cross section showing another example of the thermochromic pigment constituting the present invention.
FIG. 4 is an enlarged explanatory view of (a) appearance and (b) cross section showing another example of the thermochromic pigment constituting the present invention.
FIG. 5 is an enlarged explanatory view of (a) the appearance and (b) the cross section showing another example of the thermochromic pigment constituting the present invention.
FIG. 6 is a graph showing the discoloration behavior of a heat-decolorable thermochromic composition.
FIG. 7 is a graph showing the discoloration behavior of a color memory retaining thermochromic composition.
FIG. 8 is a graph showing the discoloration behavior of a heat coloring type thermochromic composition.
[Explanation of symbols]
  1. Metallic glossy temperature-changing heat-shrinkable plastic film
  2 Heat-shrinkable plastic film
  3 metallic luster pigment layer
  4 Thermal discoloration layer
  5 Thermochromic pigment
  51 Thermochromic composition
  52 Wall membrane
  53 Dimple
  t₁  Complete color temperature of reversible thermochromic composition with heat decoloring or color memory retention
  t₂  Color development start temperature of reversible thermochromic composition with heat decoloring or color memory retention
  t₃  Decoloration start temperature of reversible thermochromic composition with heat decoloring or color memory retention
  t₄  Complete decolorization temperature of reversible thermochromic composition with heat decoloring or color memory retention
  T₁  Color development start temperature of reversible thermochromic composition
  T₂  Complete color temperature of reversible thermochromic composition
  T₃  Decoloration start temperature of reversible thermochromic composition
  T₄  Complete color erasing temperature of reversible thermochromic composition
  ΔH_A  Hysteresis width of heat-decolorable reversible thermochromic composition
  ΔH_B  Hysteresis width of reversible thermochromic composition with color memory retention
  ΔH_C  Hysteresis width of heat-developable reversible thermochromic composition

Claims (3)

A metallic luster pigment layer in which a metallic luster pigment in which the surface of a flat glass piece is coated with titanium oxide is fixed to a binder resin in a dispersed state is provided on a part or the entire surface of the heat-shrinkable plastic film. A metallic luster-sensitive temperature-changing heat-shrinkable plastic film, wherein a thermochromic layer is laminated on a glossy pigment layer. The thermochromic layer is a layer in which a thermochromic pigment is fixed to a binder resin in a dispersed state, and the thermochromic pigment is decolored by heating from the colored state and is heated by cooling from the decolored state. Color erasure type, color development state or color memory retention type that reversibly stores the color erasure state in a specific temperature range, or color development by heating from the color erasure state, and restoration to the color erasure state by temperature decrease from the color development state The metallic luster-tone temperature-changing heat-shrinkable plastic film according to claim 1, which is selected from any one of the heating coloring types. The thermochromic pigment comprises (i) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a heat containing an essential three components comprising a reaction medium that determines the temperature at which the color reaction of both occurs. 3. The metallic glossy temperature-sensitive color-changing heat-shrinkable plastic film according to claim 1, wherein the pigment is a microcapsule-shaped pigment having a non-circular cross-sectional shape encapsulating a color-changing composition.

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